Many diabetics endure daily finger pricks to test their blood sugar levels. But advances in nanotechnology could soon mean that diabetics need endure the needle only once: to get a glucose-tracking tattoo.

Postdoctoral researcher Paul Barone and professor Michael Strano of MIT's Department of Engineering are working to develop nanoparticle tattoos that will allow diabetics to constantly monitor their glucose levels. Studies have found that it's more effective for diabetics to constantly monitor their blood sugar than to test it a few times each day. But the technology currently available for constant monitoring — such as wearable devices — offers less accurate readings than finger pricks and still requires drawing blood.

The MIT researchers are looking to develop monitoring technology that is both more accurate and allows for constant monitoring. To that end, they are cooking up a nanoparticle "ink" that detects glucose in blood.

The technology behind the MIT sensor, described in a December 2009 issue of ACS Nano, is fundamentally different from existing sensors, says Strano. The sensor is based on carbon nanotubes wrapped in a polymer that is sensitive to glucose concentrations. When this sensor encounters glucose, the nanotubes fluoresce, which can be detected by shining near-infrared light on them. Measuring the amount of fluorescence reveals the concentration of glucose.

Once the sensor tattoo is in place, the subject can wear a monitoring device over the tattoo. Since the monitor will be in such close proximity to these subdermal sensors, the readings should be far more accurate than with wearable monitors. Strano and Barone say they're still a ways away from conducting human trials, but animal trials may be just on the horizon.